Method and apparatus for dispensing gas material



0d. 7, 1941. G. H. zENNl-:R- ETAL 2,257,897

METHOD AND APPARATUS FOR DISPENSING GAS MATERIAL` Filed Feb. 28, 1939INYENTORS avm? I Wawy/5MM 2f ATT RNEYS Patented Oct. 7, 1941 METHOD ANDAPPARATUS FOR DISPENSING GAS MATERIAL George H. Zenner and Odd A.Hansen, Kenmore,

N. Y., assignors to The Linde Air Products Company, New York, N. Y., acorporation of Ohio Application February 28, 1939, Serial No. 258,902

8 Claims.

This invention relates to a method and apparatus for dispensing a gasmaterial having a boiling point below 233 K., and particularly to amethod and apparatus for dispensing gas material in the liquid phase,such as liquid oxygen, in a manner involving relatively little loss.

The invention has for its object generally the provision of an improvedmethod together with suitable apparatus for dispensing valuable gasmaterial of the character indicated in a manner which conservessubstantially all the so-called "blowdown" and residual gas material inthe gas phase.

More particularly, the invention has for its object the provision ofprocedural steps and suitable apparatus for carrying out the same insuch a manner that consumer systems which incorporate receiving vesselsor containers may be serviced and supplied with gas material in theliquid phase while at the same time providing for the reliquefaction oiall ora substantial part of the gas material in the gas phase which hasheretofore been vented to the atmosphere.

Another object is to provide an arrangement oi' Aapparatus for supplyingconsumer systems with gas material of the character indicated in theliquid phase in a manner which employs a relatively small number ofso-called cascaded vessels, i. e., vessels arranged to discharge oneinto another at different or increased pressures, for effecting thetransfer of the gas material from a vessel or container which transportsthe material to a vessel or container which receives the material at theconsuming installation and generally contains gas material in the gasphase at a relatively high pressure.

Another object is to provide an arrangement for supplying consumersystems with gas material of the character indicated in the liquid phasefrom transport containers which are closed or hermetically sealed whilein transit in a manner which satisfies present-day regulations govemingsuch transportation.

Still another object is to provide an arrangements of apparatus forfilling containers on the consumer premises, for example, containers ofthe so-called cold converter type, with gas material in theliquid phase,such as liquid oxygen, from a sealed transport container with minimumloss by blowdown, by equipping the containers with separable means forefi'ecting cascade connections whereby material in the gas phase in theconsumer container may be transferred to the transport container forreliquefaction.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the several steps and the relationof one or more of such steps with respect to each of the others, and

the apparatus embodying features of construction, combinations ofelements and arrangement of parts which are adapted to effect suchsteps, al1 as exemplified in the following detailed disclosure, and thescope of the invention will be indicated in the claims.

For a fuller understanding of the nature and objects of the invention,reference should be had to the following detailed description taken inconnection with the accompanying drawing, in which:

Fig. 1 is a view, mainly schematic but partly in section, showing anarrangement of containers with separable cascaded connections forservicing a consumer installation in accordance with thel invention; and

Fig. 2 is a similar view showing a modification.

In consumer 'installations which utilize low boiling point liqueed gasesfor industrial purposes, such as liquid oxygen, a vaporizing device isgenerally provided, which converts gas material from the liquid phase tothe vapor phase and elevates it to a pressure suitable for industrialapplications. A storage container for receiving periodically supplies ofthe gas material in the liquid phase for the vaporizer is generallyincorporated and the. servicing of such installations cbmprisesdelivering suitable charges to the receiving container from a transportcontainer whenever required.

In order that such an installation or system may be operatedeconomically, losses of gas material should rst be reduced to the lowestpractical amount, and, second, deliveries of gas material to the systemshould be made in the largest practical amounts. There are, of course,

present limits to the amount of the charge which may be transported anddelivered to the receivers at consumer installations. It is desirable,therefore, to provide servicing arrangements for filling the receiversat the consumer installations .category of liquefied gases of thecharacter indicated may be transported on the highways at a pressure nothigher than 25 lbs/sq. in.gauge unless certain rigid specifications forthe construction of the container are adopted. As a consequence,containers for transport service under pressure have heretofore beenprohibitorily expensive, and shipments as a rule are made in containersopen to the atmosphere. By far the largest losses of gas material arethose occasioned by the escape oi material in the gas phase from thetransport container while in transit.

in accordance with the practice of the present invention, in order toapproach the ideal zero losses, provision is made for transporting thegas material in a substantially tlcsfn l transport container, whereprecaution has been tellen to prevent the internal pressure fromexceeding 25 lbs/sq. in.gauge.

The step o transf r'rig the gas material in the liquid phase from ti'reimport container to a receiving vessel, such a cold converter at theconsumer installation, is eflected under the acceleration oi pressurefrom material in the gas phase withdrawn rorn the consumer system, thewhole charge being delivered at 'one time from the transport containerto the receiver. The original charge of gas material in the transportcontainer as a result completely displaced and replaced by material inthe gas phase. This discharging step may be practiced in connection withtwo or more containers that are to be filled.

The transfer ci t. e gas phase to the transport container is preferablypracticed in a manner which e-ects a reliquefaction of at least aportion of the gas phase transferred, although it may be practicedmerely as a step eiectng gas pressure equalization. Accordingly, thereis provided, in addition to the usual liquid phase trans.-

, fer connection, a gas phase equalization connection, which connectsthe gas space in the receivlng container to the interior of thetransport container. The portion of this connection entering thetransport container is preferably provided with a gas difiuser that isadapted to be submerged below the lowest substantial liquid surface inthe transport container. Another portion or branch may be provided whichcommunicates with the normal gas space when desired. The gas phasetransfer may be effected under the difference of pressure normallyexisting between the gas spaces respectively in the receiving containerand in the transport container. Power means, however, may be provided inassociation with the gas phase transfer connection for effecting thetransfer at any desired rate. Such power means advantageously has theform of a power-driven gas pump in the gas transfer line.

Referring now to the drawing, and particularly to Fig. 1, I denotes thebase of a consumer installation on which is disposed a liquid receivingcontainer II that has a liquid withdrawal connection I2 leading to aliquid vaporizing device I3. The gas material in the gas phase from thisvaporizing device may be fed into gas storage receiving cylinders I4 orinto a service pipeline I5 which is regulated by means of a pressureregulating valve, shown diagrammatically at IB. Any suitable connectionsof this character may be employed to this end, for example, as shown inthe U. S. patent to Smith, 1,942,944.

The liquid phase transfer connection is shown as having an inlet Illeading into the receiving container I I and has a controlling valve I9.This connection also preferably includes a heat insulated pressureiilling hose 20 that is detachably connected to the inlet I8 at one endand at the other to a liquid withdrawal connection 2| of a transportcontainer shown at 22 mounted on a truck chassis 23. 'I'hese containersmay be of any suitable size, for example, a capacity for liquid which.when converted into gas occupies 50,000 cubic feet at atmosphericpressure.

The gas phase transfer connection is shown at 213 consisting of asuitable pipe leading from the gas space of the receiving container IIto the interior of the transport container 22; there being included aseparable coupling 25. A valved branch 2B depends from the connectioninto the gas space of the container 22, a second valved branch 21 beingprovided with a gas diffuser, as shown at 28, which is connected at apoint such as to be normally below the ordinary working levels of theliquid in the container 22. To build initial pressure in the containerto effect the discharge of liquid, the container 22 is also pro- `vided.with suitable pressure building means, for

example, an air-heated pressure building coil, as shown at 29 and taughtin U. S. patent to leylandt, Reissue No. 18,876. A filling andevaporation escape connection is also provided for the transportcontainer, as shown at 3U.

in normal operation, the invention is practiced with the apparatusdescribed, and a service delivery of liquefied gas, for example, ofliquid oxygen is elected to the container I I, by delivering atransported charge to the consumer installation in the transportcontainer 22, the transportation being carried out with the evaporationconnection 30 closed. This connection is,

of course, closed at all times except when the transport container isbeing filled at the production plant.

When it is desired to effect transfer of the charge from the container22 to the container II, the liquid phase transfer connections areestablished by coupling the hose 20 in place, and the gas phase transferconnections established by similarly coupling the parts of connection 2|at 25. When these connections are established, the latter is ilrstopened and the material in the gas phase, which is at high pressure,allowed to pass from container II into container 22 in order to equalizethe pressures. For this purpose, only the valve in the branch 21 isopened. This allows the material in the gas phase to pass through theliquid phase in container 22 and to condense at leastfin part. Thisresults in a relatively low equalization pressure in the connectedcontainers and dissipates the original high gas pressure that initiallyobtained in container II without loss. The valved branch 28, in thisarrangement, is used only in the event that it is desirable or necessaryto introduce the gaseous material directly into the gas space of thecontainer 22.

When this gas phase transfer step is completed, the valves in line 24being closed, a nonequilibrium pressure may be and preferably is builtin the transfer container by means of the pressure building coil 29. Theliquid phase transfer connection through the hose 20 is opened as soonas a. suitable pressure obtains in the container 22.

The transfer of gas material in the liquid phase is continued under theacceleration of the pressure thus provided'until the transfer of all theliquid phase has been completed. It is thus seen that the liquid phaseis replaced by material ln the gas phase at a relatively low pressure.When the liquid phase transfer connections are dlaconnected, the liquidphase withdrawal outlet 2I is closed.

The container 22 is now returned to the production plant where thereturned charge of material in; the gas phase is withdrawn. The returnedmaterial may then be reliqueed in any suitable manner, for example, bythe steps of the process disclosed in U. B. patent to Heylandt, ReissueNo. 19,031. Metering of the material returned is advantageouslyaccomplished by weighing. 1

In the modification shown in Fig. 2, the gas phase transfer connectionincludes power means for effecting the gas phase transfer. Such meansare here shown as comprising a power-driven turbine gas pump 24,disposed in the gas phase transfer connection 2l on the transportcontainer. The power for operating the same is advantageously suppliedfrom the truck which effects the transportation of the container 22.This is illustrated in the form of an electric motor I5 coupled to drivethe pump 34; the motor, in such instance, being preferably connected tobe supplied with electric current from a battery or generator on thetruck. In this arrangement, the pressure building means, such as coil 25in Fig. l, may advantageously be dispensed with. Accordingly, none isshown in this modification. Otherwise, the construction and arrangementof apparatus is the same as that shown ln Fig. l.'

In the operation of this form of the invention, the charge of liquefiedgas to be delivered to the consumer receiver is transported to the placeof use in container 22 with its inlet closed, as in the form shown inFig. 1. When at the place of use, the liquid phase transfer connectionsare established along with the gas phase transfer connections, and thena gas phase equalization is practiced, as was described in connectionwith the form shown in Fig. 1. In this case, however, the pump 24 isstarted and the valved branch 21 iirst opened. The material in the gasphase blown through the liquid phase in the container 22 as a result ispartly condensed. This is continued until a desired low pressure isattained in the container il, when the valve in branch 2l is opened andthat in branch 21 closed` Pressure is now built in the gas space of thecontainer 22 to a desired value by the vapor transferring action of pump84 and the valves in the liquid phase transfer connection opened. The

discharge of liquid consequently takes place under the accelerationprovided by gas pressure thus built in the container 22, the conduit 24being closed until substantiallyv all the liquid is forced out. Theliquid withdrawal connection 2| is thereupon closed, the transferconnections uncoupled. and the truck with a charge of material in thegas phase in container 22 returned to the production plant.

While the step of discharging at one time has been here described astaking place continuously, transferring liquid from the container 22 tocontainer Il, it is obvious that container il might well have comprisedtwo or 'more smaller containers of such size as to receive completelythe discharge from the container 22 when thus sent out on a servicingtrip.

Since certain changes in carrying out the above method and in theconstruction set forth, which embody the invention. may be made withoutdeparting from its scope. it is intended that all matter contained inthe above description or shown in the accompanying drawing shall beinterpreted as illustrative and not in a limiting sense.

Having described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. The method of dispensing a gas material having a boiling pointtemperature at atmospheric pressure less than 233 K. to a consumersystem having a liquid .phase receiver and means for storing anddelivering material in the gas phase at a desired high pressure, whichcomprises the steps, in combination, of transporting to such system acharge of gas material in the liquid phase in a transport containerwhich 4is e closable to the atmosphere, transferring gas phase along adesired path for equalizing purposes from said receiver to saidtransport container when closed to the atmosphere preparatory todischarge, effecting reliquefaction of at least al ing to such system acharge of gas material in the liquid phase in a transport containerwhich is closable to the atmosphere, transferring gas phase along adesired path for equalizing purposes from said receiver to saidtransport container when closed to the atmosphere preparatory todischarge, applying the refrigeration ofl the liquid phase in saidcontainer to said transferred gas phase by causing the same to entersaid container at a point below the liquid level therein in order toreliquefy at least a portion of the gas phase transferred, and thendischarging liquid phase from said container while substituting gasphase.-

3. The method of dispensing a gas material having a boiling pointtemperature at atmospheric pressure less than 233 K. to a consumersystem having a liquid phase receiver and means for storing anddelivering material in the gas phase at a desired high pressure, whichcomprises the steps, in combination, of transporting to such system acharge of gas materialv in the liquid phase in a transport containerwhich is closable to the atmosphere, transferring gas phase along adesired path for equalizing purposes from said receiver to saidtransport container when closed to the atmosphere preparatory todischarge, applying the refrigeration of the liquid phase in saidcontainer to said transferred gas phase by passing at least a portion ofthe gas drawn from said path into said liquid container at a point belowthe liquid level therein in order to liquefy in said container at leasta portion of the gas phase so transferred, building a nonequilibriumpressure in said container, effecting a discharge of liquid phase whilesubstituting gas phase, and returning the substituted gas phase to theproduction plant for reliquefa-ction.

4. In apparatus for dispensing gas material having a' boiling pointtemperature at atmosf pheric pressure below 233 K., the combination witha consumer system having a container for receiving and storing a chargeof such gas material in the liquid phase and means for distributing gasmaterial in the gas phase at a desired high pressure of a heat insulatedtransport container for servicing said system provided with means forclosing the same to the atmosphere at will, means for establishingliquid phase transfer communication between said receiving container andsaid transport container, and additional means for establishing gasphase transfer communication between said system and said containers,said last-named means including a connection leading to the gas space ofsaid transport container and a gas phase condensing means in saidtransport container and extending below the normal liquid level therein;whereby at least a portion of the gas phase transferred from said systemto said transport container may be liquefied therein and conservedthereby avoiding the necessity for blowdown tothe atmospherepreparatory`to transfer of liquid phase. l A

5. In apparatus for dispensing gas material having a. boiling pointtemperature at atmospheric pressure below 233 K., the combination with aconsumer system .having means for distributing gas material in the gasphase at a desired high pressure and incorporating a receiving containerfor liquid phase, of a heat insulated transport container for servicingsaid system provided with means for closing the same to the atmosphereat will, said transport container being of a capacity such that it maybe completely discharged into said receiving container during aservicing period, means comprising a connection for establishing liquidphase transfer communication between said receiving container and saidtransport container, and additional means comprising another connectionfor establishing gas phase transfer communication between saidcontainers, said last-named connection comprising a branch leading tothe gas space of said transport container and an independent portionhaving a gas diffusing device in said transport container and'extendingbelow the normal liquid level therein; whereby at least a portion of thegas phase transferred from said system to said A transport container maybe liquefied therein and conserved. l

6. In apparatus for dispensing gas material having a boiling pointtemperature at atmospheric pressure below 233 K., the combination with aconsumer system having means for distributing gas material in the gasphase at a de sired high pressure and incorporating a receiver forliquid phase, of a heat insulated transport container for servicing saidsystem provided with means for closing the same to the atmosphere atwill, means for building a non-equilibrium pressure in said container,means comprising a connection for establishing liquid phase transfercommunication between said system and said container. and additionalmeans comprising anmesma? container may be liquefied therein.

7. In apparatus for dispensing gas material having a boiling pointtemperature at atmospheric pressure below 233 K., thecombination with aconsumer system having means for distributing gas material in the gasphase at a deaired high pressure and incorporating a receiver for liquidphase, of a heat insulated transport container for servicing said systemprovided with means for closing the same to the atmosphere st will,means for building a non-equilibrium pressure in said container, meanscomprising aconnection for establishing liquid phase transfercommunication between said system and said container, additional meanscomprising another connection for establishing gas phase transfercommunication between said system and said container, said last-namedconnection being provided with a gas phase transfer pump and formed withbranches. one of which communicates .with the gas space of saidcontainer and another extending below the normal 'liquid level thereinand terminating with a gas dinusing device; whereby at least a portionof the gas phase transferred from said system to said container may vbetransferred quickly and liquefied therein.

8. The method of dispensing a gas material having a boiling pointtemperature at atmospheric pressure less than 233 K. to a consumersystem having a liquid phase receiver and means for storing anddelivering material in the gas phase at a desired high pressure. whichcomprises the steps. in combination, of transporting to such system acharge of gas material in the liquid phase in a transport containerwhich is closable to the atmosphere, transferring gas phase from saidreceiver to said transport container when closed to the atmosphere,transferring by the aid of mechanical force an additional quantity ofgas from said receiver to said transport container. applying therefrigeration of the liquid phase to at least a portion of thevtransferred gas phase by causing the same to pass into said container ata point below the level of the liquid therein. and discharging liquidphase from said container while substituting gas phase.

GEORGE H. ZENNER ODD A. HANSEN.

